<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    手机号码：<input type="number">
    <button>发送</button>
</body>
</html>
<script>
    var bth=document.querySelector('button');
    btn.addEventListener('click',function(){
        var time=60;//定义剩下的秒数
        btn.disabled=ture;
        btn.innerHTML='还剩下'+time--+'秒';
        var timer = setInterval(function(){
            if(time==0){
                clearInterval(timer);
                btn.disabled=false;
                btn.innerHTML='发送';
            }else{
                btn.innerHTML='还剩下'+time--+'秒';
            }
        },1000);
    });
</script>